Unwinding machine



Dec. 10, 1946. R. MCC. JOHNSTONE 2,412,509

UNWINDING MACHINE Filed June 13, 1942 6 Sheets-Sheet 1 17 i 52 4 19 '1 l Y W Dec. 10, 1946. R. we. JOHNSTONE 2,412,509

UNWINDING MACHINE Filed June 13, 1942 6 Sheets-Sheet 2 Dec. 10, 1946. R. we. JOHNSTONE UNWINDING MACHINE Filed June 13, 1942 6 Sheets-Sheet 3 Dec. 10,1946. R. M C. JOHNSTONE 2,412,509

UNWINDING MACHINE Filed June 13, 1942 e Sheets-Sheet 4 In y //////////////l. ///////l//I1 A erm zue Dec. 10, 1946.

UNWINDING MACHINE Filed June 13, 1942 R. M C. JOHN STONE 6 Sheets-Sheet 5 Dec. 10, 1946. R. MCCI. JOHNSTONE 2,412,509

unwmnme MACHINE Filed June 13, 1942 6 Sheets-Sheet 6.

Patented Dec. 10, 1946 UNITED STATES PATENT OFFICE Claims.

The principal object of this invention is to provide a novel and highly efficient mechanism for assuring continuous uniform tension on a web of material as it is being drawn from a predetermined source, and while the invention is herein illustrated in connection with an unwinding machine, wherein the said source of. the web is a parent roll from which the web is withdrawn, it will be understood that the mechanism forming the subject of the invention is capable of use as a uniform tensioning means in connection with webs drawn from other sources.

In the attached drawings:

Figure 1 is a view in perspective of an unwinding machine made in accordance with my invention; 1.

Fig. 2 is a view in perspective from the opposite side of the machine shown in Fig. 1;

Fig. 3 is a sectional view as viewed on the line 33, Fig. 2;

Figs. 4 and 5 are fragmentary views in perspective of the portion of the machine shown at the extreme right in Figs. 2 and 3;

Fig. 6 is a sectional view on the line i5, Fig. 5;

Figs. 7 and 8 are sectional views on the lines 1-1 and 8-8, respectively, of Fig. 6;

Fig. 9 is a sectional view corresponding to Fig. 7 showing the parts in a different position of adjustment;

Fig. 10 is an enlarged vertical sectional view through the braking mechanism shown at the extreme right-hand end of Fig. 3 but viewed from the opposite direction;

Fig. 11 is a section on the line I, Fig. 10; 12 is a section on the line |2-|2, Fig. 3; 13 is a section on the line |3|3,' Fig. 12; 14 is a section on the line H-ll, Fig. 3; 15 is a section on the line |5-|5, Fig. 3,

.16 is a section on the line lS-Ii, Fi 15.

The machine disclosed in the drawings as an embodiment of my invention consists essentially of a frame I having means for rotatably supporting a parent roll 2 and the shaft '3 to which this roll is secured; a. means for retarding the rotation of the roll 2, said means taking the form, in the present instance, of a friction brake I; a so-called nerve roll 5 which operates in a loop of the traveling web 6 as the latter is drawn from the parent roll 2 and which is sensitive to the pull of the web and is tensioned by suitable means against the pull; and a highly sensitive means, hereinafter described, for operatively connecting the nerve roll with an actuating means for the brake whereby displacement of the nerve roll due to variations in the tension in the web will automatically actuate the brake to thereby modify the tension as may be required to maintain it substantially constant.

More specifically, the shaft 3 of the parent roll 2 is supported in the frame in journals and 3, the journal 1 being adjustable through the medium of a hand wheel 9 so as to afford a. means for aligning the shaft 3 in the frame. The journal 8, as best' shown in Figs. 4 and 5. is of the split type and comprises a bottom portion which receives the shaft 3, and a top or cap portion H which is hinged on the frame and which may be adjusted between a retracted position, as shown in Fig. 4, and an advanced position, as shown in Fig. 5, wherein the said cap portion engages the top of the shaft and thus retains it in the member The cap I2 is provided with a pivoted latch I3 which when the cap is in the operative position is adapted to pass under the shoulder ll of the journal member so as to lock the cap |2 in the operative position. The shaft 3 is provided with spaced collars |5, |5 which may be adjusted to abut the opposite ends of the journal cap l2 when the latter occupies the operative position, as shown in Fig. 3, and the hinge pin It for the cap I2 is in the form of a worm or a screw havingthreaded engagement with the cap structure and being mounted for rotation in lugs l1, IT on the journal bracket l8. A spiral gear I9 is secured to one end of the worm l6, and this gear meshes with a second spiral gear 2| which is suitably mounted for rotation in the bracket l8 and which may be turned through the medium of a hand wheel 22, see Fig. 1. This provides for adjustmentof the journal cap l2 axially of the shaft 3, and through the medium of the collars l5, l5 for a corresponding axial adjustment of the shaft and of the parent roll 2 in the frame.

The brake 4 is best shown in Figs. 3, l0 and 11. As shown in Fig. 3, the entire brake structure is supported upon a bracket 23 secured to one end of the frame, and the outer face 24 of this bracket forms one of the friction surfaces against which a rotary brake disk 25, which is connected to the shaft 3 by means hereinafter described, operates in the braking function. This disk 25, as best shown in Fig. 10, has a splined connection with a shaft 25, the splines 21 extending to a sleeve 28 in which the shaft 26 is longitudinally adjustable. This sleeve is journaled on anti-friction bearings 29 in the bracket 23, and the shaft 26 extends from the sleeve towards the adjoinin and means is provided for confining the disk un der variable pressure between the plate 3| and the friction surface 24 of the bracket 23. Coiled springs 34 are supported on the bolts 32 between the opposed faces of thebracket 23 and the plate 3| and exert pressure tending to move the plate 3| away from the disk 25. Supported on the outer ends of the bolts 32 is a yoke 35, and Journaled in this yoke is a shaft 36, to one end of which is secured a lever 31 and which carries intermediate the sides of the yoke 35, as shown in Fig. 11, a cam 33, see also Fig. 3. Embracing the periphery of the cam and supported thereon by anti-friction bearings 33 is a contact ring 4|, and this ring is adapted to engage one end of a screw 42 threaded centrally into the plate 3|. It will be apparent from the foregoing description that actuation of the lever 31 and consequent rotation of the shaft 36 will cause the cam 38 either to advance the plate 3| toward the frictional surface 24 of the bracket 23 and against the pressure of the springs 34, or will release the plate so as to permit the springs 34 to retract the plate from the surface 24 and the brake disk 25. It will be noted that the screw 42 has secured thereto, by suitable means, a lever 43 by means of which this screw may be turned in the plate 3| to adjust it longitudinally in the latter.

Pivotally connected at 44 to. the lever 31 is a second lever 45. One end 46 of this lever extends into proximity to one side of the upper end of the lever 31, and a spring 41 is suitably supported between the end 46-of the one lever and the opposed side of the lever 31. The other end 43 of the lever 45 is connected to a sylphon bellows 43. This end of the lever 45 is also engaged bya transversely projectingflange at the free end of the lever 31, and this flange 5| is normally held against the side of the lever'45 by pressure of the spring 41. With this arrangement, the spring 41, which may be calibrated as required, controls the maximum force which may be applied, through the lever assembly and the cam 38 against the screw 42, and thereby also controls the maximum pressure that may be exerted upon the brake disk 25 between the friction surfaces 33 and 24. In other words-when the lever 45 is moved in a clockwise direction by expansion of the sylphon 49, see Fig. 10, thereby to increase the pressure upon the disk 25, the force applied to the plate 3| through the cam 33 will increase only to a point where the calibrated spring 41 will yield. If at any time it is desired to release the brake 25 independently of the lever system 31-45 and the associated actuating mechanism, this can be done by an adjustment of the screw 42 through the lever 43.

The shaft 26 is coupled to the shaft 3 by a coupling device best illustrated in Figs. 6 to 9, inclusive. As therein shown, the end of the shaft 3 is flattened at opposite sides to provide a terminal tongue 52. The longitudinal edge of the tongue within the area where the tongue adjoins the body of the shaft are beveled, as indicated at 53. Engaged with the tongue 52 is a sleeve 54, this sleeve having at one end a slotted recess 55 for reception of the tongue 52. Opposite sides of this slot are formed by a pair of hardened steel inserts 56, 56 which are set into and the sleeve 54 then rotated with respect to the shaft 3, or vice versa, the beveled surfaces 53 will permit the tongue 52 to assume the relative position in the sleeve shown in Fig. 9, wherein the corners of the outer unbeveled portion of the tongue will overlap and will lie behind the steel inserts 56, thereby locking the sleeve on the shaft.

The other end of the sleeve 54 is provided with a cylindrical opening 53, the outer end of which is intersected at two sides by hardened steel inserts 53, 59 of the same character as the inserts 56 and similarly, securedin the sleeve. The shaft 26 is provided with a projecting tongue 6| which is flattened at its opposite sides to permit of its insertion into the opening 53 between the inserts 53, and a cylindrical head element 62 is secured to the end of the tongue 6| after insertion so as to lock the shaft 26 in the sleeve 54, It will be noted that since the shaft 26 is free-for axial movement in the bracket 23, axial adjustment of the shaft 3, as previously described, will not affect the coupled relationship of the said shafts. In passing from the parent roll 2 to the nerve roll 5, the web 6 passes around an idler pulley 63 which is suitably journaled in the frame I..

The nerve roll 5 is joumaled on anti-friction bearings 64' for free rotation upon a shaft 65, an

this shaft mounts rollers 66 which travel on tracks 61 on the frame. Anti-friction bearings 68 are also interposed between the rollers 66 and the shaft. This provides for free rotational movement of the roller 5, and also for translational movement of this roller in the frame and with respect to the relatively fixed idler roller 63.

Secured to each end of the shaft is a pinion 69, and each of these pinions meshes with a rack 10 secured to the frame. These pinions and theirracks function to maintain the shaft 65 and the roll 5 continuously in parallel relation with the idler roll 63. Secured to one end of the shaft, see Fig. 16, is a second pinion 1|, and this the outer end of the sleeve 54, as best shown in fully inserted in the recess 55, as shown in Fig. 6,

pinion meshes with a rack 12 which is slidably supported in suitable guides 13 in the frame, see Fig. 15, and which is secured at one end to a "sylphon bellows 14, this bellows being operatively connected through a suitable duct 15 with the sylphon 49, which as previously described is operatively associated with the brake device 4. The pinion 1| is somewhat smaller than the pinions 63 so that any movement of the shaft 65 on the rails 61 will result in a longitudinal displacement of the rack 12 of a predetermined order. This displacement ofthe rack 12 will be transmitted through the hydraulic system, composed of the sylphons 49 and 14 and their connecting duct 15, to the brake 4, with a resulting actuation of the latter.

Supported on anti-friction bearings 16 on one end of the shaft 65, see Fig. 13, is a roller 11, and to the roller 11 is attached a cable 18 which extends, in parallel relation to the guide rails 51, to a horizontal sheave 19 supported on the frame, and thence to a vertical sheave 8|, also supported on the frame. The free depending end of the cable 18 supports a weight 82 which constitutes a predetermined load on the nerve'roll 5, tending to pull this roll against the loop of the web 6. Adjustment of the weight controls the amount of tension in the web, as will hereinafter appear. Obviously the weight 82 may be replaced by a spring or other suitable means,,preferably variable, for loading the nerve roll.

The operation of the device will be apparent from the foregoing description. Any variation in the tension of the web 6 immediately affects the nerve roll and will be accompanied by a translational movement of this roll. If the tension in the web decreases for example, the nerve roll 5 under the action of the weight 82 will tend to move toward the right, as viewed in Figs. 2 and 15, and this movement of the roll will result in a movement toward the right, as viewed in the latter figure, of the rack 12. The resulting contraction of the sylphon 14 will in turn effect a corresponding expansion of the "sylphon 49 and a movement of the lever 45 in a clockwise direction, as viewed in Fig. 10. This will cause a movement of the cam 38 in a direction to increase the pressure on the plate 3|, and will thereby increase the frictional drag on the brake disk 25. This increased drag on the parent roll 2 will cause an increase in the tension in the web, thus compensating for the original loss of tension. If for any reason the tension of the web should increase, the device will operate in the opposite phase to decrease the retarding action of the brake on the parent roll.

By reason of the use of the hydraulic system, the differential racks, and lever and cam elements in the transmission link between the nerve roll 5 and friction brake 4, the device is highly sensitive in reacting to and compensating variations in web tension, and is highly efficient in maintaining a substantially uniform tension in the web.

I claim:

1. In a machine for maintaining uniform tension in a traveling strip, means for imposing a drag on the strip, said means being adjustable to vary said drag and to thereby regulate the tension, a floating nerve roll arranged for engagement with the strip, a shaft constituting a. journal support for said roll, and means for tensioning said nerve roll so as to exert a force on the strip tending to deflect it from a normal path, guide means for said roll including a pinion secured to the roll shaft and a relatively fixed rack engaging said pinion, a second pinion of differing diameter than the pinion first named and similarly secured to the roll shaft, a rack engaged with said second pinion and supported for longitudinal movement'with respect to the first-named rack, and hydraulic means operatively connecting the said relatively movable rack with the drag means whereby changes in tension in the strip detected by the roll may be translated into compensating adjustments of the drag.

2. In a machine for maintaining uniform tension in a traveling strip, means for imposing a drag on the strip, said means being adjustable to vary said drag and to thereby regulate the tension, a floating nerve roll arrangement for engagement with the strip, and means for tensioning said nerve roll so as to exert a force on the strip tending to deflect it from a normal path, a supporting shaft upon which the said nerve roll is journaled, guide means for said r011 including a pinion secured to each end of said shaft and a relatively fixed rack engaging said pinion, a second pinion of differing diameter than the pinions first named and similarly secured to the shaft, a, rack engaged with said second pinion and supported for longitudinal movement with respect to the first-named racks, and hydraulic means operatively connecting the said relatively movable rack with the drag means whereby changes in tension in the strip detected by the roll may be translated into compensating adjustments of the drag.

3. In an unwinding machine of the type comprising a journal support for a parent roll, a brake operatively associated with said roll and a floating element engaged with the strip and sensitive to variations in tension in the strip; said brake comprising an adjustable member for imposing a variable drag on the roll opposing withdrawal of the strip material from the latter, a cam for actuating said member to increase the drag, resilient means operating in opposition to the cam and tending to reduce the drag, actuating means for the cam, and hydraulic means for transmitting impulses from the said element to the actuating means whereby changes in tension in the strip detected by the element may be translated into compensating adjustments of the brake, said cam actuator including means for limiting the amount of force imposed upon the cam by said hydraulic means.

4. In an unwinding machine of the type comprising a journal support for a parent roll, a brake operatively associated with said roll, and a floating element engaged with the strip and sensitive to variations in tension in the strip; said brake comprising an adjustable member for imposing a variable drag on the roll opposing withdrawal of the strip material from the latter, a cam for actuating said said membe to increase the drag, resilient means operating in opposition to the cam and tending to reduce the drag, actuating means for the cam, said means including a lever connected to the cam, a second lever pivotally connected to the lever first named, resilient means interposed between said levers, stop means for holding said levers normally in predetermined relative position against the tension of said spring, and hydraulic means connected with the secondnamed lever for transmitting impulses from the said element to the brake whereby changes in tension in the strip detected by the element may be translated into compensating adjustments of the brake, said levers being arranged to move as a unit until the force applied to the lever by said hydraulic means is suiiicient ,to overcome the tension of said spring, movement of the firstnamed lever being terminated by contraction of the spring.

5. In a machine for maintaining uniform tension in a traveling strip, means for imposing a drag on thestrip, said means being adjustable to vary said drag and to thereby regulate the tension, a floating nerve roll arranged for engagement with the strip, and means for tensioning said nerve roll so as to exert a force on the strip tending to deflect it from a normal path, a rollsupporting shaft upon which the said roll is journaled, guide means for said roll including a pinion secured to the roll shaft and a relatively fixed rack engaging said pinion, a second pinion of differing diameter than the pinion first named and similarly secured to the roll shaft, a rack engaged with said second pinion and supported for longitudinal movement with respect to the firstnamed rack, and means operatively connecting the said relatively movable rack with the drag means whereby changes in the tension in the strip detected by the roll may be translated into compensating adjustment of the drag.

ROBERT MCC. J OHN STONE. 

